Abstract:
Processes and systems for producing glass fibers having regions devoid of glass using submerged combustion melters, including feeding a vitrifiable feed material into a feed inlet of a melting zone of a melter vessel, and heating the vitrifiable material with at least one burner directing combustion products of an oxidant and a first fuel into the melting zone under a level of the molten material in the zone. One or more of the burners is configured to impart heat and turbulence to the molten material, producing a turbulent molten material comprising a plurality of bubbles suspended in the molten material, the bubbles comprising at least some of the combustion products, and optionally other gas species introduced by the burners. The molten material and bubbles are drawn through a bushing fluidly connected to a forehearth to produce a glass fiber comprising a plurality of interior regions substantially devoid of glass.
Abstract:
A combustion apparatus includes a combustion chamber having multiple combustion zones. A first wind box is in communication with the first combustion zone to feed the fuel to be fed into the combustion chamber for initial combustion of the fuel within the first combustion zone. A second wind box has a reburner in communication with the second combustion zone. The reburner is configured to feed fuel, a reagent and a first portion of the flue gas to be recycled to the second combustion zone into the second combustion zone to reduce nitrogen oxide emissions of the apparatus. A third wind box is in communication with the third combustion zone to feed air to the third combustion zone to complete the combustion process.
Abstract:
In a burning air feeding device (9) of alternating heat-exchanging type, the feed of burning air and the discharge of a burned exhaust gas are performed at the speeds of 80 to 200 m/sec. A burner structure (4) is constituted such that a low-calorie fuel gas is preheated with the heat of a precombustion high-calorie fuel gas till the low-calorie fuel gas reaches a mixing starting zone (CA), and such that the precombustion high-calorie fuel gas and the low-calorie fuel gas are burned together in the mixing starting zone (CA). The sum (Q1+Q2) of an air quantity (Q1) fed from the hot air feeding ports of a plurality of fuel gas burning devices and an air quantity (Q2) of a precombustion air to be mixed with the high-calorie fuel gas in the plural fuel gas burning devices is set to 1.02 to 1.10 times as high as the stoichiometric air quantity (Qs) necessary for the combustion, and the ratio (Q2/(Q1+Q2)) is set within the range of 0.011 to 0.047.
Abstract:
A combustion apparatus (1) is generally composed of a principal part (5), a supplementary part (6) and a burner port assembly (3). Four metal plates (7,8,10,11) constituting the principal and supplementary parts (5,6) are pressed to have in them several protuberances and recesses. These metal plates are laid one on another to form in them some hollow spaces and sealed regions. These hollow spaces communicate with each other to form a thin gas passage (22) together with a thick gas passage (73) in this combustion apparatus (1) in such a manner that its condition of thick and thin fuel combustion is rendered more stable.
Abstract:
A combustion apparatus (1) with a burner port assembly (3) comprises an elongated first array of main burner ports (53) for jetting and burning a fuel gas mixture of a concentration to make main flames. The combustion apparatus (1) comprises at least one second arrays of auxiliary burner ports (63) for jetting and burning a further fuel gas mixture of a different concentration to make auxiliary flames, wherein the second arrays of said auxiliary burner ports (63) extend along the first array of said main burner ports (53). The burner port assembly (3) is constructed using inner and outer wall segments (52) together with outermost wall segments (52a,52f) or bands (58). One of the bands (58) faces the corresponding one of said outermost segments (52a,52f) so as to define between them collateral burner ports (61a,61b).
Abstract:
Nitrogen oxides, NOx, resulting from the excess air combustion of solid fuels in a combustor or burner in a furnace are reduced. By introducing sufficient additional fuel to the combustion gases in the furnace downstream of the primary combustion zone, a fuel rich gas zone is created in a temperature range that favors the conversion of NOx to nitrogen, N2. Further downstream sufficient additional air is added to complete the combustion of any unburned fuel. Alternatively, the fuel rich gas zone can be confined to a central region of the furnace. In that case, final combustion takes place when the fuel rich gas mixes with the untreated gas further downstream in the furnace. The preferred embodiment of this invention is to introduce the additional fuel in said downstream combustion zone as solid particles dispersed in aqueous droplets of varying size that vaporize throughout the furnace gas zone being treated. The dispersed solid fuel particles burn as they evolve from the droplets. Special injectors atomize the aqueous droplets into the combustion gas and disperse them throughout the optimum NOx reduction temperature zone. Alternatively, the fuel rich combustion zone can be produced with injection of liquid fuel droplets. A third alternative is to use pyrolysis gas emitted from the partial gasification of a solid fuel. A fourth alternative is to inject pulverized coal particles or shredded biomass particles into the optimum NOx reduction zone. The present staged combustion method using these fuels and fuel injection methods can be combined with other NOx reduction processes to yield large overall NOx emission reductions.
Abstract:
The low-emission swirling-type furnace is designed to burn organic fuel and it can be most advantegeously used for dust combustion. A low-emission swirling-type furnace, according to the invention, comprises a combustion chamber (1) with a prismatic dry-bottom hopper (5) having a slot mouth, and an undergrate blast inlet means (7) disposed thereunder. The furnace includes at least one burner (2) formed by at least a pair of ducts (2a,2b ) lying one above the other and intended for supplying the air-fuel mixture. The ducts (2a, 2b) are each provided with a device (3, 4) for controlling the "air/fuel" ratio, ensuring such a ratio between the amount of air and the amount of fuel in each of the ducts (2a,2b ) that for the overlying duct (2a), this ratio turns out to be invariably higher than for the underlying duct (2b). The longitudinal axes of the ducts (2a, 2b) are preferably so inclined that the angle between the longitudinal axis of the duct (2b) and the projection of this axis onto the furnace wall for an underlying duct is less than that for the overlying duct (2a). Furthermore, the furnace may also be provided with a means (8) for supplying the fuel of a specific size composition into each duct. During operating of such furnace, three functional zones are generated in the heating volume, namely: the ignition and active combustion zone, the reduction zone, and the reburning zone. This results in a reduced discharge of nitrogen oxides, along with an economical performance of the furnace.
Abstract:
The present invention is related to methods and systems for preventing the release of nitrogen oxides with combustion flue gases emitted to the atmosphere. The invention is specifically directed to the removal of nitric oxide, nitrogen dioxide, and nitrous oxide from flue gas in stationary combustion systems. The methods of the invention improve efficiency of conventional reburning and advanced reburning processes by two key improvements, including the injection of a reducing agent into the reburning zone and the use of promoters, which considerably enhance NO.sub.x control. The promoters are metal-containing compounds that can be added to the reducing agents. These improvements allow either one or two stages of reducing agent injection for greater NO.sub.x control.
Abstract:
A pulverized coal combustion burner includes a pulverized coal nozzle, and secondary and tertiary air nozzles provided in concentric relation to the pulverized coal nozzle. A flame stabilizing ring is provided at an outlet end of the pulverized coal nozzle. A separation wall is provided within the pulverized coal nozzle to divide a passage in this nozzle into two passages. A pulverized coal/air mixture flows straight through the two passages, so that recirculation flows of the pulverized coal/air mixture are formed in proximity to the outlet end of the pulverized coal nozzle. As a result, the ignitability of the pulverized coal, as well as a combustion rate, is enhanced, thereby reducing the amount of discharge of NOx.
Abstract:
A power generating combustion system and method are provided with a first stage combustion system that may include a wet oxidation reactor or a direct contact boiler and a second stage combustor including a stoichiometric burner to produce the substantially complete combustion of a wide range of fuels and mixtures of fuels to produce combustion products usable in generating power. The system design temperatures and pressures allow the substantially complete combustion of garbage, municipal and industrial waste and low quality fuels to generate power.